Cryopreservation-induced decrease in heat-shock protein 90 in human spermatozoa and its mechanism.

AIM

To study the protein changes of spermatozoa associated with sperm motility during sperm cryopreservation and its mechanism.

METHODS

In 18 healthy men, the seminal sperm motility and HSP90 levels were studied before and after cryopreservation using SDS-PAGE, Western blotting and computerized image analysis.

RESULTS

The sperm motility declined significantly after cryopreservation (P<0.01). The average grey level and the integrated grey level of sperm HSP90 before cooling were 34.1+/-3.2 and 243.0+/-21.6, respectively, while those after thawing were 23.2+/-2.5 and 105.7+/-28.5, respectively. Both parameters were decreased significantly (P<0.01). No HSP90 was found in the seminal plasma before and after cryopreservation.

CONCLUSION

HSP90 in human spermatozoa was decreased substantially after cryopreservation. This may result from protein degradation, rather than leakage into the seminal plasma.